The present disclosure relates generally to computer system data storage management, and, in particular, to file relocation management for reducing data access time on a data storage device.
File management systems, such as a log-structured file system (LFS), may store data as a circular log, writing data sequentially to the log. This approach attempts to maximize write throughput on a data storage device by avoiding costly seeks based on an assumption that repositioning of a read/write head used to access the data storage device is not required prior to beginning a new write cycle due to sequential file locations. One reason that this approach is expected to be efficient is that a higher percentage of accesses to the data storage device, such as a hard disk drive (HDD), are assumed to be writes, with frequently read data held in a local cache memory. However, this assumption can breakdown when data stored in the file system are read more frequently than anticipated. Additional complications can arise when the data being read via the file system is read too infrequently or in such a large quantity that cache memory is ineffective. Using a strict sequential approach to writing data ignores potential delays that can occur when files are accessed at different frequencies at non-sequential locations. For example, new files may be written progressively in a sequential manner, but reads to other locations on the data storage device can occur at any location. Thus, frequent read/write head movement can still occur as the read/write head moves between read and write locations. Since a larger degree of movement causes a greater access delay, frequent read/write head movements can lead to significant access delays, even in an LFS.
In order to remain competitive, computer system manufactures are constantly looking for ways to improve system response time by reducing delays. Therefore, it would be beneficial to develop an approach to manage file locations on a data storage device that improves system responsiveness. Accordingly, there is a need in the art for file relocation on a data storage device to reduce data access time.